WASHINGTON – The bill that comes every month is evidence enough: Cable rates are steadily rising. Now, there’s a prediction that the average customer’s bill will hit $200 a month by 2020.

Market research firm NPD Group finds the average TV subscriber paid $86 in 2011, but predicts that cost will rise to $123 by 2015 and to more than $200 by 2020.

The cost could drive even more families toward free over-the-air programming or online streaming.

NPD finds 16 percent of American households don’t currently have TV or satellite service, and 20 percent of pay-TV customers surveyed said they’d likely cancel their service if their favorite shows were available online.

Some consumer groups, such as Consumers Union, have pushed for a la carte cable systems, that would allow households to choose their own channels rather than predetermined packages which included channels they aren’t interested in.